Noob question -- 2001 Path temp gauge

[dpsw]

Hi all.

I just wanted to try posting this again. I hope someone can help!

I have a 2001 Pathfinder and my temp gauge stopped working. Once in a while it comes up to where it should but the majority of the time it just sits at C.

I've read guys talking about sending units and I wanted to see if I could diagnose this one myself. I'm a total noob, though, and I don't know where to start. If I could find it I could put a meter on it and see if there's any signal coming from it. Then I'd just have to replace it, which would be another question!

Thanks ahead of time.

DW

[Pwnin O'Brien]

Well, there are two things that could cause this issue: a faulty instrument cluster or a faulty thermal transmitter. Unfortunately the thermal transmitter is only connected to the instrument cluster, so the ECU doesn't know if the thermal transmitter is operating properly or not. This means that you will need to manually test the thermal transmitter first to see if it is operating within spec. One issue with testing the thermal transmitter is that it is in an inaccessible spot, so you will need to measure at the instrument cluster. First you will need to remove the instrument cluster from the vehicle. Now, find pin #18 on the white harness that you unplugged from the instrument cluster. You want to meter that wire with the engine cold and with the engine hot. Here's what I would recommend:

With the cluster removed from the vehicle, measure the impedance of that wire with the engine cold. Then plug the cluster back in and warm the vehicle up to normal operating temperature. Once the vehicle is warmed up, remove the instrument cluster and re-measure the impedance of that wire. With the vehicle cold the impedance should measure over 210 ohms. With the vehicle warmed up, it should measure less than 53 ohms. Post your measured impedance's here and we can see if that is your issue. If that is not your issue than further testing is necessary.

[dpsw]

Pwnin:

Thanks for the head start. I'll check that out and post back!

DW